Fire, smoke, and fumes in confined spaces, such as multi-floor buildings, can be extremely life threatening. Frequently, if fire originates in the space between a floor and ceiling of such a structure, the fire, and resultant smoke and fumes, will tend to spread to other open spaces in the building, especially to open spaces above the point of origin of the fire.
The reasons behind this spread of fire, smoke, and fumes to higher areas are varied. The areas between conduits, piping, and the like, and floors/ceilings through which they pass, are known as "through-penetrations". If not fire protected, through-penetrations offer areas of low resistance to fire, smoke, and fumes, and in essence serve as "chimneys". These areas may be filled with commercially available fire retardant and intumescent putties, caulks, wraps, or mats, known in the art as "firestops". Representative firestop products are disclosed in product brochure number 98-0701-3508-6 (published 1990) from Minnesota Mining and Manufacturing Company (3M). The 3M products are currently known under the trade designations "CP 25WB" "CP 25N/S" "CP 25S/L" and "Firedam" (caulks); "MPP-4S" and "MPS-2" (moldable putties); "FS-195" and "CS-195" (moldable strips); and "Interam" and "Interam E-5" (mats). These products are variously described in assignee's U.S. Pat. Nos. 3,916,057; 4,273,879; 4,305,992; 4,364,210; 4,433,732; and 4,467,577.
The above firestop products and others have been widely used for reducing or eliminating the chimney effect for through-penetrations and pass the rigorous American Society of Testing Materials (ASTM) fire endurance test (ASTM E-814) after intumescing and charring. However, even if the fire is contained in the space between one floor and the next highest floor by a firestop, serious hazards remain. This is because many multi-level buildings will have joints between exterior walls and floors constructed as illustrated in side elevation in FIG. 1. Shown is "vision" or "spandrel" (i.e., ornamental) glass 10, which may form the exterior of a building. (Alternatively, 10 may be concrete, marble, and the like.) Typically, an inorganic fibrous material 12 is installed for thermal insulation (referred to in the art as a "curtain wall"). The inorganic fibrous material may be glass fiber, mineral wool, and the like. Thermal insulation 12 is fastened to a "mullion" 13 (term of art for the metal frame system for the exterior glass and thermal insulation) with screws or other means as shown at 16 and 18. Also shown is a concrete floor slab 20 which is typically supported by an I-beam 22. A "safing" material 14 is also typically installed, which may be glass fiber, mineral wool, or other type of inorganic fibrous material insulation. One or more Z-clips 15 is typically provided for mechanically supporting safing 14.
It is important to note that an air space 24 is left in the construction illustrated in FIG. 1, between the mullion, thermal insulation, and the vision or spandrel glass (typically about 2.5 cm gap). As heat is generated in the interior of the building in the vicinity of such a wall/floor joint, if the temperature is high enough, the binder in mineral wool insulation will oxidize, exposing the air space 24 to fire, smoke, and fumes, and allow the chimney effect discussed above. (Glass fiber insulation will begin to disintegrate at about 565.degree. C., causing similar problems.) Heat from the fire may then distort the mullion system, cause the concrete floor to deform, and may ultimately cause the vision or spandrel glass (or other exterior wall material) to shatter. Obviously, falling debris present a hazard to people outside of the building, such as fire control personnel and on-lookers, and fire hoses may be cut by falling glass chards and other debris. Thus, it would be highly advantageous to keep the temperature of the thermal insulation as low as possible, for all of these reasons.
As explained by Nicholas, J. D., in "Making Joint Systems Fire-Resistive" NFPA Journal, March/April (1991), pp. 98-102, at 100:
The crucial difference between joints such as those illustrated in FIG. 1! and through-penetrations is movement. Firestops are designed for static applications because the movement of penetrating items, such as pipes, is normally absorbed by bellows joints and directed away from the firestop. Thus, the firestop remains relatively static. However, joints do move, responding to expansion, contraction, shear, and rotational joint movements caused by thermal variations, seismicity, settlement, and wind sway . . . If the fire barrier deteriorates, permanently deforms, or cannot cycle, it may not be able to maintain its fire rating. (Emphasis supplied) PA0 (a) a first layer material having first and second major surfaces, the first layer material comprising inorganic fibers and a binder in the form of a flexible mat, as above described; PA0 (b) a second layer material adhered to the first major surface of the first layer material, the second layer material comprising a flexible intumescent fire retardant composite material as above described; PA0 (c) a third layer adhered to the second layer, the third layer comprising inorganic fibers which are the same or different than the first layer as above described; and PA0 (d) a fourth layer adhered to the third layer, the fourth layer comprising a flexible intumescent fire retardant composite material. PA0 (a) a first layer material having first and second major surfaces, the first layer material comprising inorganic fibers and a binder, formed as a flexible mat, as above described; PA0 (b) second and third layers adhered to the first and second major surfaces of the first layer, respectively, the second and third layers comprising inorganic fibers which are different from those of the first layer; PA0 (c) fourth and fifth layers adhered to the second and third layers, respectively, the fourth and fifth layers comprising a flexible intumescent fire retardant composite material. PA0 (a) an insulating component positioned substantially within the shape defined by the mullion upon attachment to the mullion and having interior and exterior facing surfaces, the insulating component comprising an inorganic material capable of providing thermal insulation for the building; PA0 (b) a safing component positioned substantially between an exterior butt end of the floor and the insulating component; and PA0 (c) a fire barrier comprising a flexible composite material, the fire barrier having first and second portions, the first portion positioned adjacent and substantially parallel to the insulating component, and the second portion positioned substantially adjacent the safing component upper surface, the second portion having first and second ends, the first end attached to the top surface of the butt end of the floor and the second end attached to the first portion, and the first portion of the fire barrier attached to the mullion, wherein the second portion has at least one curved portion which provides slack, thus allowing the fire barrier to effectively lengthen and shorten during relative movement of the wall and floor. PA0 (a) an insulating component positioned substantially within the shape defined by the mullion upon attachment to the mullion and having interior and exterior facing surfaces, the insulating component comprising an inorganic material capable of providing thermal insulation for the building; PA0 (b) a safing component positioned substantially between an exterior butt end of the floor and the insulating component; and PA0 (c) a fire barrier comprising a single length of flexible composite material, the fire barrier having first and second ends, the first end positioned substantially adjacent and fastened to the insulating component and mullion at a point no lower than the safing, the second end fastened to the top surface of the exterior butt end of the floor, wherein the flexible composite has at least one curved portion which provides slack to allow the fire barrier to effectively lengthen and shorten during relative movement between the floor and wall. These embodiments are advantageously used when the portion of the insulating component below the safing is mineral wool or other high temperature resistant material. The "short" fire barriers cannot be employed with glass fiber insulation installed below the safing since glass fiber insulation will begin to disintegrate at about 565.degree. C., as previously mentioned. (The time-temperature curve of the ASTM E-119 test reaches temperatures of about 925.degree. C.)
Note that the terms "firestop" and "fire barrier" have different and precise meanings in the art, the former describing materials used in through-penetrations and other static joints, the latter used to denote materials used in movable (dynamic) joints.
There is thus a requirement for a flexible composite material which can be used in conjunction with conventional thermal insulation to form a system which provides not only adequate thermal insulation under static conditions, but which also provides the required fire barrier properties for dynamic joints such as illustrated in FIG. 1. The present invention is drawn toward meeting this need. Currently, as explained by Nicholas at page 100, there exists no fire endurance standards for fire barriers since standard tests have not been available.
U.S. Pat. No. 4,977,719 (LaRoche et al.) describes an expansion joint for interior or exterior use including a fire barrier comprised of a fire resistant inorganic refractory fabric sheet which supports resilient fire resistant inorganic refractory fibers. German patent application DE 3632648 (Figen et al.) describes a rain-proof and fire-resistant movable profile system for a freely movable connection of an available building wall, especially a wall of an older building, and a butt-jointing attachable exterior wall, consisting of three individual profiles which can be moved with respect to each other. Neither reference suggests the composites, systems, or methods of the present invention.